How to remove row wise sorting in R dataframes - r

Question

I have the following code written to take bind two columns and create a data frame.
complete<-function(directory,id){
x<-vector()
y<-vector()
files<-list.files(directory,full.names=TRUE)
for(i in id){
x[i]<-i
y[i]<-sum(complete.cases(read.csv(files[i])))
}
d<-na.omit(data.frame(x,y))
colnames(d)<-c("id","nobs")
rownames(d)<-1:nrow(d)
print(d)
}
I have the following test case :
complete("specdata",30:25)
id nobs
1 25 463
2 26 586
3 27 338
4 28 475
5 29 71
6 30 932
I am not able get the output in the order called by the function. i.e.
id=30 as the first value and id=25 as the last value. How do I get to disable automatic sorting by id?

Answer 1

We can change for(i in id) to for(i in seq_along(id)) to loop by the sequence of 'id'. Also, make some necessary changes in assigning x[i] and y[i].
complete<-function(directory, id){
x<- vector()
y<- vector()
files<-list.files(directory,full.names=TRUE)
for(i in seq_along(id)){
x[i]<- id[i]
y[i]<-sum(complete.cases(read.csv(files[id[i]])))
}
d<-na.omit(data.frame(x,y))
colnames(d)<-c("id","nobs")
rownames(d)<-1:nrow(d)
print(d)
}
Testing
complete('specdata', 25:30)
#id nobs
#1 25 4
#2 26 0
#3 27 1
#4 28 1
#5 29 2
#6 30 13
complete('specdata', 30:25)
# id nobs
#1 30 13
#2 29 2
#3 28 1
#4 27 1
#5 26 0
#6 25 4
NOTE: The values are different because the 'specdata' directory that I have is from a previous coursera link. They might have updated the data